Carburetor



Jan. 31, 1939. L H. MESSINGER. JR

CARBURETOR Filed Dec. 16, 1936 .53 IN V EN TOR. LESTER H. MESS\NGER,

A TTORNE).

Patented Jam 31, 1939 CARBURETOR Lester H. Messingcr, Jr., Trumbull,Conn, assignor to Messingcr Devices, Incorporated, Bridgeport, Coma, acorporation of Connecticut Application December 16, 1936, Serial No.116,070

3 Claims.

'll 'hisv invention relates to new and useful improvements incarburetors. l

The invention providesmeans whereby the fuel discharged by a vacuumoperated accelerator pump of a carburetor is forced by the pump into areceptacle and is drawn from said receptacle into an engine fed by thecarburetor only while the carburetor throttlevalve is open and theengine is operating.

' The objects and advantages of the invention will. become apparent froma consideration of the following detaileddescription taken in connectionwith the accompanying drawing wherein there is shown asatisfactoryembodiment of the invention. However, it is to be understoodthat the invention is not iimitedto the details disclosed but includesall such variations and modifications as fall within the spirit of theinvention and the scope of the appended claims.

In the drawing: Fig. 11 is a view partly in side elevation and partly insection showing a carburetor embodying the invention;

' Pig. 2 is a top plan view with parts broken away 25. and showing theinvention;

Fig. 3 is a detail sectional view showing the carburetor fuel pump indischarged position;

Fig. '4 is a plan view of a receptacle employed; l 'ig. 5' is a verticalsectional view through such 30' receptacle; 1

' Fig. 6 is a detail sectional view through the economizer valve; and Icheck valve. 1 1

Referring in detail to the drawing a carburetor of; the down draft typeis shown and the same comprises upperand lower sections ill and II I vsecured together by screws i2. Within the carburetor is any or the usualventuri i3 located 40 above the throttle valve ll. In the float chamberIi the fuel is maintainedat the level indicat- 'ed by the line it, beingcontrolled by a float (not 1 shown) regulating the admission of gasolineor other fuel from any source through a connec- 45 tion ll.

The carburetor includes a vacuum operated v fuel pump generallydesignated l8 and comprising a chamber I9 constituting the pumpcylinder. lWithin said cylinderithere is arranged pis 0 tons 20 and 2|connected by a rod 22 about which is coiled a spring 23 bearing at itsrespective ends against the piston 2t and a collar 24. In Fig. 1 spring"is compressed and the pistons 20 and 2| are in the positions occupiedby them when the. 5 pump isloaded while inFig. 3 the pump is indischarged position. The spring 23 constantly tends to maintain thepistons in the positions of Fig. 3 and to return them to such positionswhen moved therefrom.

Through a cross passage 25 the upper end of 5 the pump cylinder II isplaced in communication with the upper end of a vertical passage 26which through a lateral branch 21 communicates I with the fuel passage28 below the throttle valve It. Through the described passages suctionfrom 10 the engine, while the latter is operating, will serve to exhaustair from above the piston 2| and the piston assembly, including pistons20 and 2| and the rod 22, will be drawn upwardly compressing the spring23 bringing about load- 15 ing of the pump. That is the suction movesthe pump to the position of Fig. l.

A lateral passage 2! from the lower end of the pump cylindercommunicates through a one way valve 30 with the float chamber ii. Valve20 ll (see Fig. 7) is a flap valve including a valve proper designatedll opening downwardly and normally open to permit of the flow of fuelfrom the float chamber into the cylinder II. On downward movement of thepiston 20 under the urg- 5 ing of the spring 28 pressure is applied tothe fuel in chamber or cylinder I! and the passage 29 and valve 3| movesupwardly against its seat 32 preventing the fuel being forced back intothe float chamber. 30

Below the, pump cylinder is a well 33 communieating by way of a passage34 with a fuel jet or Fig. 7 is a detail sectional view through a nozzle35 which in the present case is the power jet of the carburetordischarging in a small venturi "a. An economizer valve 38 is arranged toclose of! communication between the jet 35 1 and the pump when thelatter is in loaded position. valve includes a stem 31 carrying a valveproper ll (see Fig. 6) and the lower end portion of the stem is guidedin a spider 39. Between the spider and the valve 38 a spring 4|] isdisposed about the stem 31 and under normal conditions is eifective tomaintain the valve on its seat. The arrangement is such that if there isno other escape for fuel as the pump dis- 4r charges then the valve 38is forced open and the fuel .dischargedthrough the nozzle or jet 35.

Arranged at one side of the body of the carburetor is a small tank orreceptacle ll adapted Iherefore, while in subsequent portions of thespecification and in the claims the part 4| is referred to as areceptacle" it is to be understood that such word is used as including aseparate tank as shown or a compartment or chamber formed in the mainbody of the carburetor or at any other convenient location.

Receptacle 4| is shown as a flat, generally rectangular device althoughthe particular shape is not controlling. It includes a body portion 42and a top or cover 43 secured in place as y screws. By means of a.vpartition 45 the interior of the body 42 is divided into chambers 46 and41 of which the latter is shown somewhat larger than the former.Threaded into the upper end of chamber is a plug 48 having meteredorifice 49 therethrough. The upper surface of the plug is flush with theupper end of the body but the top 43 is hollow in its under side so thatthe chambers 46 and." are in communication through the orifice 49.

Receptacle body 42 is provided with an inlet entering the lower endportion of the chamber 46 and with an outlet 5| from the lower endportion of chamber 41. Into these openings are threaded elbows 52 and 53respectively. On one face of the body 42 is a boss 54 having a thread-.

ed stud 55 projecting therefrom. A drilled hole 55 through the studcommunicates with themterior of the body, entering the upper portion ofchamber 41. If desired a metering plug 51 is threaded into the elbow 53so as to be removable and replaceable should an orifice of a differentsize be desired.

The passage 29 communicates with a well 58 at the lower side of valve 30and also communicating with the well, being secured by a fitting 59, isa tube 60. Such tube having its other end attached to the elbow 52 by a,fitting 5| places the'well in communication with the lower end portionof the chamber 45. Thus the chamber 45 is placed in communication withthe float chamber 15 through the valve 30 and with the pump through thelateral passage 29.. When the piston 25 is in its upper position thepump is loaded with fuel drawn from the float chamber through the valve30.

Thereafter on the suction or vacuum being reduced the spring 23 acts andthe piston 20 descends to discharge the pump. At this time the valve 35is closed and the pressure on the fuel forces valve 3!! closed and thefuel is discharged by the pump through the tube 50. Suflicient pressureto force open the valve 56 is not gen erated and such valve remainsclosed until the stem 31 is engaged by the piston 20 as in Fig. 3 whenthe valve is forced and held open until the piston is again movedupwardly to load the pump.

Heretofore in carburetors of the type shown the pump l8 discharged onlythrough the nozzle 35. The arrangement was such that the pump wasoperated to loaded'position while there was suction in the engineequipped with the carburetorand then on reduction of the suction orvacuum as by opening of the throttle valve l4 the spring 23 of the pumpwould act to discharge it and the fuel would be forced through thenozzle 35.

With such an arrangement the pump would discharge the fuel throughnozzle 35 when the engine ignition was cut off and the engine stoppedand such discharged fuel would simply run into the intake manifold andthen into the engine when not needed. Also if the engine was equippedwith an air inlet valve as shown in my Patent 2,017,914 of October 22,1935 the pump if in loaded position would discharge through nozzle 85each time the valve opened at which times it is desirable that no fuelbe fed to the engine. To overcome these difficulties and prevent wasteof fuel I provide the receptacle 4| and the connections thereto so thatat each discharge of the pump the fuel passes to the receptacleand istaken therefrom at such times as the fuel is required by and inaccordance with the air entering the engine. That is the fuel is notsquirted into the intake by the pump regardless of the air stream but issucked into the carburetor and thence the engine in proportion to theair entering the engine.

A tube 62 communicates with the lower por tion of the chamber 41 beingattached at one end to the elbow 53 by means of a fitting 63. Such tubeis attached to a wall of the fuel passage 25 by a fitting 54 andextending through such fitting and wall has its other end projectingthrough the venturi l3 forming a nozzle 55.

The receptacle 4| is mounted on the carburetor by passing the stud 55through a drilled hole in the carburetor wall so as to dispose an end ofthe stud in the upper portion of the float chamber l5. Then a nut 65 isthreaded onto the stud to clamp a portion of the carburetor wall betweenthe nut and the boss 54 whereby to secure the receptacle to thecarburetor. Thereafter an opening 61 is drilled through the nut and intothe drilled opening 55 through-the stud. Thus the-upper portion of thechamber 41 is placed in communication with the carburetor float chamberl5 above the float level.

Obviously fuel from the float chamber of the carburetor flows intothereceptacle chamber 46 until the level of fuel in chamber 45 is the sameas that in chamber l5. Thereafter as additional fuel is forced intochamber 45 ondischarge of the pump it may flow through the orifice 49and over the partition 45 into the chamber 41. Such fuel remains inchamber 41 while the engine throttle valve is closed or while the airinlet valve of my patent above referred to is open. Assuming such airvalve to be closed or absent from the engine, on opening of the throttlevalve while the engine is operating there is an increase in the suctionor degree of vacuum in the Venturi of the carburetor and fuel is drawnfrom the chamber 41 through the tube 62 into the engine. As the engineoperates under conditions causing a high degree of vacuum in the Venturiportion of the carburetor fuel'is drawn through the tube 52 until thesupply in chamber 41 is exhausted but the engine cannot draw fuel fromthe chamber 45.

The capacity of the chamber 46 is such that as the pump is drawn toloaded position should the valve 30 not release the fuel as fast as thepump requires it the additional fuel will be taken from the chamber 45to satisfy the requirements of the pump. That is during operation of theengine the chamber 46 remains full and its capacity nozzle 65 it maycontain several discharges of the pump l8. p

Hole 61 has its upper end above the fuel level in the float chamber.Owing to the presence of this hole and the hole 56 which connects it tothe interior of chamber 41, when the fuel is exhausted from suchchamber, air is drawn through tube 6! from the source and in the manner1 specified it will be clear that only air which has passed through anair cleaner will be fed into the engine as all air for the latter passesthrough a cleaner as it enters the carburetor. As the I upper end of thehole 61 is just under the dividchamber, a nozzle in the venturi, a pumpcommunicating with said fuel chamber and including a vacuum operatedmeans to move it to loaded position and spring means to operate it todischarge fuel on reduction of vacuum on said means, a receptacle, apassage connecting the discharge of the pump with the upper end portionof the receptacle whereby oneach discharge a of the pump fuel isdelivered to the receptacle, said passage communicating with said fuelchamber whereby to maintain the fuel in the passage at ,the level of thefuel in the chamber, said passage below the level of fuel therein havinga greater cubic capacity than said pump whereby V said pump in itsmovements to loaded position carburetor, means providing a passage atthe cannot exhaust the fuel from said passage and hence is preventedfrom drawing air, and a passage connecting the lower end portion of thereceptacle with said nozzle for the passage of fuel from the receptacleto an engine fed by the carburetor.

2. An attachment for a carburetor including a throttle, a fuel chamber,a fuel pump adapted to be operated to loaded position by vacuum, and

a spring means to operate the pump to discharged position, a receptacleat the outer side of said outer side of said carburetor and connectedwith said fuel chamber whereby the level of fuel in said passage is thesame as that in the fuel chamber, said passage also connected with saidreceptacle and said pump whereby at each discharge of the pump fuel isforced through said passage into the receptacle, said passage below thelevel of fuel therein having a greater cubic capacity than said pumpwhereby said pump in its movements to loaded position cannot exhaust thefuel from the said passage and hence is prevented from drawing air, anoutlet passage from the receptacle into the carburetor and throughwhich'fuel is drawn into an engine fed by the carburetor on opening ofsaid throttle while the engine is operating, a hollow bolt securedto.said receptacle and passing through a wall of the carburetor andsecuring the receptacle to the carburetor, and said hollow boltproviding a passage communicating the upper portion of said receptaclewith the interior of the carburetor above the liquid level thereinwhereby to prevent setting up of a siphonic action through thereceptacle and whereby to balance the air pressure in the receptacle andin the carburetor.

3. In a carburetor, a fuel pump adapted to be operated to chargedposition by vacuum and other means to operate the pump to cause it todischarge fuel, a receptacle of a capacity to contain several completedischarges of said pump, means connecting the receptacle with thecarburetor for the passage of fuel therethrough from the receptacle toan engine fed by the carburetor, said connecting means and receptaclearranged and constructed whereby fuel is drawn into the engine from thereceptacle only when the engine is exerting a suction pressure on thecarburetor, and means providing a passage between the pump andreceptacle whereby on reduction of vacuum on the pump all fueldischarged thereby is delivered to and retained by said receptaclewhereby to prevent waste of fuel when the vacuum pump discharges andthere is no suction on said carburetor and whereby to have such fuelavailable to the engine through said connecting means on reestablishmentof suction in the carburetor,

said passage connected with the fuel chamber of

